EDITORIALS
Evidence to action in the developing world: what evidence is needed?
Tikki Pang1
Department of Research Policy and Cooperation, World Health Organization, 20 avenue Appia, 1211 Geneva 27, Switzerland
Can it work? Will it work? Is it worth it? These three questions constantly face health policy-makers, for whom access to the most relevant and useful evidence is critical.
However, evidence in the clinical care context differs from evidence in the public health and health policy domains. It is often difficult to apply rigid hierarchies of evidence to public health policy. Although randomized controlled trials and systematic reviews are methods of choice when assessing the effectiveness of medications, complex health-care problems pose different challenges.13
Evidence providers and health policy-makers from developing countries have insisted that evidence needs to be broader than that based solely on randomized controlled trials. Observational studies, qualitative research and even "experience", "know-how", consensus and "local knowledge" should also be taken into account.
For example, Indonesia tapped into village wisdom to formulate actions and policies to combat avian influenza.4 Locally-generated evidence reformed social health insurance in Mexico5 and Thailand; it also improved primary health care in the United Republic of Tanzania6 and mental health-care policy in Viet Nam.7 In these five examples, findings were interpreted and utilized against a background of global evidence and experience from different settings.
In terms of generating the evidence, policy-makers should be involved from the start in defining the specific policy question and processes for developing the evidence base and interpreting reviews and evidence summaries. Research provides only one type of evidence, and policy decisions are invariably made within the context of other social, political, cultural and economic factors.2 Different policy questions may require different types of evidence.
Arguably, evidence for policy and action in a public health context also requires innovation beyond the health sector. As an example, policies for vaccination strategies in humans can be combined with those for animals to achieve synergies and efficiencies in resource-poor settings.8
Timeliness is another important issue. The reality is that policy-makers are under pressure to implement policies rapidly, often in the absence of relevant evidence on the likely outcomes of their decisions. What is WHO doing to ensure that national research agendas are designed to address this lack of evidence?
Through EVIPNet (Evidence-informed Policy Networks),9 WHO is working to build capacity in countries for linking the producers and users of knowledge. The Alliance for Health Policy and Systems Research and WHO are promoting more health systems research, including context-specific research that is often most needed for national decision-making.10
Evidence-based public health is an exciting and emerging field. However, it is still in its infancy, is comparatively imprecise and definitely needs more support for its further development. It bravely tries to merge the "science" with the "art" of health policy-making, and takes into account the reality that "scientific findings do not fall on blank minds that get made up as a result. Science engages with busy minds that have strong views about how things are and ought to be ..."11 A realistic view of evidence in health policy-making will serve to move the field forward for the benefit of all. 
References
1. Goldenberg MJ. On evidence and evidence-based medicine: lessons from the philosophy of science. Soc Sci Med 2006;62:2621-31.
2. Rychetnik L, Hawe P, Waters E, Barratt A, Frommer M. A glossary for evidence-based public health. J Epidemiol Community Health 2004;58:538-45.
3. Grypdonck MHF. Qualitative health research in the era of evidence-based practice. Qual Health Res 2006;16:1371-85.
4. Normile D. Indonesia taps village wisdom to fight bird flu. Science 2007;315:30-3.
5. Knaul FM, Arreola-Ornales H, Méndez-Carniado O, Bryson-Kahn C, Barofsky J, Maguire R, et al. Evidence is good for your health system: policy reform to remedy catastrophic and impoverishing health spending in Mexico. Lancet 2006;368:1828-41.
6. de Savigny D, Kasale H, Mbuya C, Reid G. Fixing health systems. Ottawa: International Development Research Center; 2004.
7. Harpham T, Tuan T. From research evidence to policy: mental health care in Viet Nam. Bull World Health Organ 2006;84:664-8.
8. Schelling E, Bechir M, Ahmed MA, Wyss K, Randolph TF, Zinsstag J. Human and animal vaccination delivery to remote nomadic families, Chad. Emerging Infect Diseases 2007;13:373-9.
9. Hamid M, Bustamante-Manaog T, Dung TV, Akhavong K, Fu H, Ma Y. EVIPNet-translating the spirit of Mexico. Lancet 2005;366:1758-60.
10. van Kammen J, de Savigny D, Sewankambo N. Using knowledge brokering to promote evidence-based policy-making: the need for support structures. Bull World Health Organ 2006;84:608-12.
11. Marmot M. Evidence-based policy or policy-based evidence? BMJ 2004;328:906-7.
1 Correspondence to Tikki Pang (e-mail: pangt@who.int).